The present invention contemplates to use spent liquor from kraft pulping and/or derivatives thereof as anti-AIDS agents for the prevention and therapy of infection by the AIDS virus.
So far, the only drug approved for therapeutic use against AIDS is azidothymidine (AZT). AZT is a nucleic acid-based derivative.
Moreover, drugs currently under development include compounds of dideoxy nucleic acid-based derivatives (e.g., dideoxycytidine, dideoxyadenosine, etc.), and sulfates of polysaccharides (e.g., dextran sulfate, etc.). However, they have problems in effectiveness from the points of toxicity, absorptivity, metabolism, etc. Thus, the development of other drugs exhibiting improved effectiveness is desired.
The present inventors have investigated the above problems diligently, and have previously applied for a patent concerning the antiviral action of spent liquor from pulping (Japanese Patent Application No. Hei 1-82691). Continued investigations have led to the discovery that, in particular, (1) spent liquor from kraft pulping (2) kraft lignin in the spent liquor from kraft pulping, and (3) sulfomethylated and sulfopropylated kraft lignins have excellent anti-AIDS activity. After confirming the effect against AIDS virus (HIV) (see Examples 1 to 4 infra), the present invention was completed.